1. Field of the Invention
This invention relates to an illumination apparatus for a microscope in which a plurality of wavelengths of light can be arbitrarily chosen, their intensities can be independently adjusted, and a specimen can be irradiated with the light at the same time, and to an image processing apparatus using this illumination apparatus.
2. Description of Related Art
Generally, fluorescence microscopes are widely used for the purpose of detecting proteins and genes in which fluorescence labeling is applied to living tissues and cells in the fields of medicine, biology, and others. In recent years, a multiple fluorescence detection technique that a specimen stained with a plurality of fluorescent dyes or a specimen revealing a plurality of fluorescence proteins is observed at a time has particularly exercised its power for the analysis of genes and the solution of intracellular structures. In the multiple fluorescence detection technique, in order to excite a multiple fluorescence specimen, a means for irradiating the specimen with illumination light of a plurality of wavelengths has widespread use. Here, important factors governing the accuracy of observation data are that time intervals of irradiation with individual wavelengths are short and the intensity distribution of irradiation light of each wavelength on the surface of the specimen remains unchanged in terms of time and space.
As conventional means for irradiating the specimen with the illumination light of the plurality of wavelengths in order to excite the multiple fluorescence specimen, an apparatus using a filter switching means to time-divide the wavelengths of excitation light (see, for example, Japanese Pat. Kokai No. Hei 09-005243) and an apparatus using two independent light sources (see, for example, Japanese Patent Kokai No. Hei 07-056092) are proposed. In addition, an apparatus dividing light from a single light source to irradiate a specimen with divided light (see, for example, Japanese Patent Kokai No. Hei 10-090608) is proposed.
The apparatus disclosed in Kokai No. Hei 09-005243, as shown in FIG. 1, is constructed so that a living tissue to be measured is previously processed with fluorescent light of a plurality of wavelengths; a filter switching means 151 in which a plurality of filters 151a for excitation light selection are set at a predetermined place in a rotary disk 151b and a filter switching means 152 in which a plurality of filters 152a for fluorescent light selection are set at a predetermined place in a rotary disk 152b are used; by synchronously rotating these disks, the living tissue is irradiated with the first excitation light and the second excitation light by time division; the first fluorescent light and the second fluorescent light, produced from the living tissue, are recorded in turn; and, for example, changes in intracellular ion concentration and in membrane potential are measured at substantially the same time.
The apparatus set forth in Kokai No. Hei 07-056092, as shown in FIG. 2, is constructed so that two light sources 161A and 161B for white light, such as xenon lamps, are used; light from the lamps, after being collected through collector lenses 162A and 162B, is transmitted through excitation filters 163A and 163B which have different transmission wavelength regions, and wavelengths are selected; and light of selected wavelengths is synthesized by a dichroic mirror 164 and is introduced into an observation optical system 165. According to this apparatus, a specimen can be illuminated with light of desired wavelengths by properly replacing the excitation filters 163A and 163B.
The apparatus set forth in Kokai No. Hei 10-090608, as shown in FIG. 3, is constructed so that irradiation light emitted from a light source 171 for irradiation is split through a splitting optical system 172 and different parts on a specimen 173 are irradiated with split light beams A and B.